Apparatus for use in the analysis of volatile liquids



Dec. 8, 1931. v, HENRl 1,835,985 I APPARATUS FOR USE IN THE ANALYSIS OF voLATILE LIQUIDS Filed June 7. 1929 Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE VICTOR HENRI, OF ZURICH, SWITZERLAND, ASSIGNOB TO UBBAIN- CORPORATION, OF NEW YORK, N. Y.

APPARATUS FOR USE IN THE ANALYSIS OF VOLATILE LIQUIDS Application filed June 7, 1929, Serial No. 369,251, and in France June 11, 1928.

In an U. S. application filed on July 23rd, 1927, Ser. No. 207,912, in the name of Mr. Victor Henri, a process is described applicable to the majority of gases or vapours and adapted to determine the nature and the proportion of the consituents of a mixture of gas or of vapours, by the analysis of the absorption spectrum of the mixture.

The present invention relates to another apparatus suitable for use in connection with the said process in ever case in which a liquid mixture can be tota y volatilized without the constituents of the mixture being decomposed, which in a large number of cases is possible only by operating at a suitably reduced pressure. Frequently it will also be advisable to proceed in stages with the volatilization of the liquid by evaporating it in successive portions so as to separate partly the constituents. In that way it will be possible to show the different constituents more clearly.

The apparatus hereinafter described enables all these operations to be easil carried out in an exact manner with a sma 1 sample of the substance to be analyzed, and it is illustrated by way of example in the accompanying drawings, in which Figure 1 is a longitudinal section, and

Figure 2 is a cross section on line A-B of Figure 1.

The apparatus is constituted b a tube 1 hermetically closed at its two en s by windows 2, 2 of quartz or other material transparent in the zone of the spectrum to be examined. This tube is surrounded by a suitably heat-insulated heating resistance 3 by means of which (by operating for instance a rheostat) the tube can be brought to a known constant temperature controlled by a suitable thermometric device such as is known in the art, or the temperature may be controlled by adjusting the flow of the electrical current while watching the temperature through the medium of an appropriate instrument as the thermometer 4. As will be shown from Figure 1, the heating resistance is held at a certain distance from the tube 1 so that the heat shall be uniformly distributed owing to the intermediate layer of air.

The heating resistance 3 affords a passage for a pipe 5 through which the vapours to be examined are introduced into the tube 1. This pipe-5 terminates at the other end in a chamber 6 of a small electric heater 7 which may be provided, like the first, with a suitable thermometric device for the control of the temperature of the heater 7, or as stated above, the temperature may be controlled by adjusting the flow of the electrical current in any desired way while watching the temperature through the medium of an appropriate instrument such as the thermometer 8.

The winding 9-9 of the heater 7 is divided into two parts, one of which is movablc examined. The other end 11 of the chamber 6 is extended by a pi e 12 provided with a cook 13 and connecte to a pump or to any other apparatus by means of which a good vacuum can be produced both in the chamber 6 and in the tube 1 through the pipe 5.

The operations take place in the following manner:

The tube 1 having been placed in the path of the beam emitted by the source chosen. and analyzed by the spectral apparatus, is raised to a fixed temperature which is high enough to prevent the vapours of the liquid to be analyzed from condensing. The thin glass bulb containing the substance to be analyzed has been previously introduced into the chamber 6. A vacuum is then produced in the apparatus, the cock 13 is closed, and the bulb is broken, for instance by dropping it with a hard heavy body contained in the chamber 6, which can be easily done by turning the Whole apparatus round the axis of the tube 1 at right angles to the axis of the chamber 6. The temperature of the chamber 6 is then gradually raised in order to produce a slow evaporation of the liquid, and the successive spectra of absorption of the gaseous phase more and more rich in products with a high boiling point, are examined.

When the evaporation is finished, and the temperature of the chamber 6 is equal at least -teria-l transparentiin the zone ofthe spectrum 60 v sistancewhereby-the\tennoerature:ofthe tube j nay be controlled, a small electric heater,

to that of the tube 1, the quantitative meas urements are eliected, which are greatly facllitated by the preceding determinations.

It must be pointed out here that in the case of organic vapours and of a large number of mineral vapours, the coeflicient of absorption in the ultra-violet zoneis sufiicientiy great to enable the tube 1 to be made of a reduced length, so that its handling is greatly 'facili tate'd. Asa rule, a 3004mm.thickness ofwapours ivill be sufiicient in most cases.- It" is only when the volatilization Without decomposition of-the substance to 'be examined ne- J cessitates exceedingly low pressures that it will be necessary to employ materially longer tu'hes. T he above description of an apparatus according to the invention, and of the finethod of using it, wi1 l make the ct genof a chamberabsorbing rays oi light, thetemeral definition of the invention'much clearer. The invention consists 1n the comb nation vic'roii HENRI.

V perature of which can be regulated at will. 7' ,wwith an evaporat on chamber distinct from the tormerand also of a temperature which canbe ire rulated at will and independently -of that .of the first chamber, the Whole enabling,thevspectrumof vopours of a liquid to be examinedsuccessively during its evaporaan arbitrary pressure. What I claim 1SI Annpparatus for-use inthe analysis'of tion and after its total evaporation and at -YQliLtilB liquids hy mean-s of the absorption I SPBCtPHHIOfdZhGlI vapours,comprising. a-tube,

ofthe spectrum'to he examined for closing thc render-of =.the tube forming chamber "for .absorblngzraysof l ghha heat nsulatedrheat-r ingresistaneerheld at-a certain distance from and around the said tube electrical connections 'forlsaid resistance whereby the temperv vindowsiof-material transparent in the Zone V ature of the tube may be controlled, a small electric heater, an evaporation chamber with in the 'S11Cl16l8(;t110-h6)it6I', electrlcal connections forsaid electric heater Whereby the tem vperature of theevaporation chamber may be controlled, a pi pe connecting together the absorption chamber and the evaporation chainiberjanda second pipe connected. to one end of the evaporation chamber for producing. y

chamber and in .a. vacuum both in the latter the above tube.

7.2. An apparatuscomprisinga tube adapted to be rotated about its axis, Windows of mato be examined for closingthe ends of the tube forming a chamber for absorbing rays -ofilight, a heat insulated heatingresistance vheld at'a certain distance from andvaround -.the said tube, electricalconnections for said rean evaporation chamber ithin the-said electric heater, the .axis'o'f vthe above tube and ;;e\-!ap orationchamber being at right .anglesto 

